Method of making pneumatic tires



June 27, 1933. c. G. HOOVER METKHOD OF MAKING PNEUMA-TIC TIRES FiledDeo. 1, 1951 A M m Srwentor Clair 6. Hoover lll/11111 Gttornega PatentedJune v27,v 193.3.

y UNITED STATES PATENT OFFICE CLAIR e. noovnn. or more', bmo, AssreNonTo aum rms'rorm 'rmx a RUBBER v comm, or vnunon, omo, a conrom'rronoromo HETHOD F vHAXIN'G PNEUIATIC TIRES applicati med recenter 1, 1931.serial no. 578,266.

This inventionI relates to a method` for making tires and particularlyto improvements in the so-called flat-band method of manufacture.

In vthe manufacture of tires by the {latb-and method, the tire buildingmaterials'are applied on a drumto form an endless band, the inner pliesthereof first, then the beads at the margins of the drum, then the outerplies,

tread sidewals, etc., the margins of thevplies ,being folded about thebeads. The drum is usually provided with reduced bead seats in the caseof straight side or inextensible bead tires.

` After the tires are thus built up upon the drums they are expandedfrom at shape to horseshoe shape in cross section prior tovulcanization. During this operatlon they plies about the beads arenecessarily required to adiust themselves to the new shape andheretofore, due to the adhesion of the plies to the beads, distortion ofthe plies about the beads has resulted, such distortion in the completedlocalized stresses and heating.

tire 'being detrimental probably because of lIt has been found that thisdefect in the manufacture of tires by the Hat band method is easily,economically and effectively overcome by providing beads, either thecores or covers of which are coated with .a suitable lubricant beforeincorporation into the tire. TheA preferred -class of lubricants are.those such as paraffin or the like capable of melting and beingabsorbed in the carcass of the tire' during vuleanization. In thiswaythe loop o f tire plies about the beads is permitted to turn easilyabout the beads when the tire is adjusting itself to its finished sha eduring i the expanding operation and accor ingly the tire assumes itsfinal shape without distortion about the beads.

The invention will be better understood by Figure 2 shows the tire'after expansion to pneumatic tire shape;

Figure 3 is an enlarged detail section through the tire in fiat form atabead theregf siowing` the lubricant about the core of the Figure 4 is asimilar view showing the lubricant about the cover of the bead; and

Figure 5 is an enlarged section at the bead in the finished tire, thelubricant having been absorbed into the tire during vulcanization.

Referring tothe drawing, the numeral i designates a tire shown in Figure1 in flat band form and in Figure 2 after expanded to tire shape. Thebeads of the tire are shown at 11, 11' and usually have the inner plies12, 12 of thetire folded about the same as clearly appears in Figures 3and 4 with the outer plies 13, 13 lapped thereover. The beads 11 usuallyare made up with covering plies 14 and 15 of tire building materialfolded about, the same and providing a iipper lfor. an-

choring the beads in the tire. A chafing strip 16 is also usuallyapplied.

The present invention consists in providing a coating of a lubricanteither at 17 about the bead, Figure 3, or at 18about the ply 14 of thebead covering, Figure 4, before the beads i are incorporated into thetire. The lubricant employed must be suitable lto lubricate adjoiningrawrubber surfaces and is preferably one which will not affe'ct thesubsequent vulcanization of the bead structure into an integral bondedconstruction and accordingly, a lubricant such as paraffin is suggested,

this material being melted at vulcanizing A temperature and, absorbedinto the rubber and fabric body of the bead.

When 'the tire is then expanded to tire shape,'the loops of rubberizedfabric turn about the beads without distorting as clearly shown inFigure 5 to the positions they as- .Y

sume in the finished tire. Upon vulcanizetion of the tire to its final.form the parain is melted and absorbed into the tire and the variouspartsof the beads are vulcanized intro .an integral structure.

Modification Aof the invention of course may be resorted to' withoutdeparting from the spirit thereof or the scope of the alp-A pendedclaims.

What is claimed is:

1. The method of making pneumatic tires comprising building a tirecarcass in Hat, endless band form, buildin a beadhaving an inextensiblecore and a fa plying a coating of parain between said core and saidcover, incorporating the bead in said carcass, expandin the tire band totire shape, and vulcanizing tEe tire.

2. The method of making pneumatic tires comprising building a tirecarcass in flat, endless band form, buildin a bead having aninextensible core and a fa ric cover, applying a coating of paraiiinabout said cover, incorporating the bead in said carcass, expanding thetire band to tire shape, and vulcanizing the tire. y

3. The method of making pneumatic tires com rising building a tirecarcass in flat, endless and form, building a bead having aninextensible core and a fabric cover, applying a lubricant between saidcore and said cover, incorporating the bead in said carcass, expandingthe tire band to tire shape, and vul- 1 canizing the tire.

4. T he method of making pneumatic tires comprising building a tirecarcass in flat, endless band form, building a bead having aninextensible core and a fabric cover, applying a lubricant about saidcover, incorporating the bead in said carcass, expanding the :ire bandto tire shape, and vulcanizing the 5. The method of making pneumatictires comprising building a tire carcass inflat, endless band form,building abead for said tire, applying a coating of parain about saidad, incorporating' the bead in said carcass, expanding the tire band totire shape, and vulcanizing the tire.

6. T he method of making pneumatic tires comprising building a tirecarcass in flat, endless band-form, building a bead for said tire,applying a lubricant about said bead,

incorporating the bead in said carcass, ex-

panding the tire band to tire shape, and vulcanizing the tire.

7. In the method of building tires in flat band form, the step ofapplying a coating of paraffin about the bead of the tire before it isincorporated in the tire.

bric cover, ap-

8. In the method of building tires in flat band form, the step ofapplying 'a lubricant about the bead of the tire before it isincorporated in the tire, said lubricant being absorbable into the tireduring vulcanization.

9. The method of making pneumatic tires comprising building a tirecarcass in fiat, endless band form` of rubberized fabric plies, buildinga bead for said tire, applying a coating of parain about said bead,lapping 'said plies about said bead to incorporate the bead in saidcarcass, sliding the fabric plies about said bead while expanding thetire band to tire shape, and vulcanizing the tire.

10. The method of making pneumatic tires comprising building a tirecarcass in flat, endless ban'd form of rubberized fabric plies, buildinga bead for said tire, applying a lubricant about said bead, lapping saidplies about said bead to incorporate the bead in said carcass, slidingthe fabric plies about said bead while expanding the tire band to tireshape, and vulcanizing the tire.

11. A bead ring for pneumatic tire carcasses comprising an inextensiblecore having a coating of lubricant thereon and an outer coveringl offabric rotatable about the inner core.

12. A bead structure for pneumatic tires comprising an inner core havinga coating'of lubricant thereon which is absorbed by rubber attemperatures of vulcanization, and an outer covering of fabric rotatableupon the bead core. v

13. A pneumatic tire band comprising a bead structure having aninextensible core therein, a coating of lubricant on the core which isabsorbed by rubber at temperatures of vulcanization, and plies of fabricwrapped about the coated core and being rotatable thereupon, the pliesof fabric being incorporated into the tire carcass.

14. A bead structure for pneumatic tires comprising a core, a coating oflubricant.

thereon, and a multi-'ply fabric covering disposed about said core andcoating.

. In witness whereof, I have hereunto axed my sig-nature this 13th dayof November,

4 cnam ci.v Hoovaii.

